The present invention is generally related to enophile functionalized polymer particles, nano-sized inorganic metal particles, and preparations of both. Also, the present invention is related to a novel rubber composition comprising nano-sized inorganic metal particles and a method of improving the properties of a rubber composition.
As a transition between atomic and bulk material, nano-sized material has new, surprising and important properties such as solubility, optical properties, electronic properties, magnetic properties, chemical reactivity, and chemical selectivity etc. The potential benefits of nano-sized material are pervasive, including information technology, medicine and health, material and manufacturing, aeronautics and space exploration, environmental and energy etc. Various prior arts have described the preparation, analysis, physics, and chemistry of nano-sized materials, for example, “Physics and Chemistry Of Metal Cluster Compounds” edited by L. J. De Jongh, Kluver Academic, Dordrecht/Boston/London, 1994, and references thereof. For nano-sized materials that are synthesized from polymer matrices, examples include clusters of zinc sulfide, lead sulfide and cadmium sulfide from polymethyltetracyclododecene (J. Am. Chem. Soc. 1993, 115, 4409-4410); inorganic crystallites or clusters of cadmium sulfide, cobalt sulfide, nickel sulfide and zinc sulfide from functionalized diblock copolymers of polystyrene and poly-2-vinylpyridine (Synthetic Metals, 1991, 41-43, 1159-1162); semiconductor particles from an ethylene-methacrylic acid copolymer (Inorganic Chemistry, 1988, 27(3), 435-436); lead sulfide clusters from ethylene-methacrylic acid copolymers (J. Chem. Phys., 1987 87(12), 7315-7322); cadmium sulfide in a Nafion polymer film (J. Phys. Chem., 1984, 88, 980-984); spherical cadmium sulfide particles with a diameter of one micrometer or smaller, from an ionically conductive polymer membrane (Nafion) (J. Am. Chem. Soc., 1983, 105, No. 23, 7002-7003); metal clusters that are less than 100 Angstroms in diameter from a nonconductive polymer matrix (Chem. Mater. 1992, 4, 885-894); Cu2+ complexes formed with anionic polyamidoamine dendrimers (J. Am. Chem. Soc. 1994, 116, 661-671); and PAMAM-SBDs/Mn(II) complexes (J. Phys. Chem. 1996, 100, 11033-11042).
The exploration and exploitation of nano-sized inorganic metal particles, however, have not so far been adequately and satisfactorily carried out for industrial application purpose. Advantageously, the present invention provides a method of preparing nano-sized inorganic metal particles using enophile functionalized polymer particles as host. Equally advantageously, the present invention provides a method of improving the properties of a rubber composition, such as that used to construct tires by formulating nano-sized inorganic metal particles into the formulation, and thereby improving several properties, including bonding rubber, tensile strength, tear strength, and wet traction, among others.